Hot gas motor with phase changer



3 1950 F. L. VA'N WEENEN ET AL 2,508,315

HOT GAS MOTOR WITH PHASE /CHANGER Filed Aug. 31, 1945 mmm LAMBERTUJ m1WEENEN& mum HENDRIK JTIGTER ATTOR/Vf' Y Patented May 16, 1950 11:.

HOT GAS MOTOR WITH PHASECH-ANGER Francisco's Lambertus van Ween n andWillem" Hendrik Stig ter; Eindhoven; Netherlands, as signers to:Hartford National Bank & Trust Company, Hartford, Conni as trustee Anueation rmgust 31, 19215,. Serial No. 613',945

This invention pertains to a hot-gas engine, and moreparticulanly to adevice for controlling th indicated power bymodifyihg the phase anglebetween the Working piston v and the displa'cer piston;

we; known that by modifying the phase oflthe niovementsof'theworkingpiston and'of the dis placer piston; itispossible to regulate-the coursethe pressure in the cycle and consequently ailso' the 'power ofthemotorrs. A=known deVioefr regulating this phase angle: consists ofseparate drives: for the piston andforthe displacer, in which eventthe-displacer is driven bytwo dinerentl y arranged-eccentrics, which areconnected the rod of! the displacer through the interm'ediary of alinkbeam; which construction is also found piston steam engines which"com prise a slide valve as the steam distributingmember. Such a:linkconstruction lias th'e drawback thattherma'ss which is tobe m'ovedto and fro large: which drawback is especially prevalentinenginesarunning at a high speed;

Axpr i ma'ry object of this-invention is"to--o've'r-- comektheaboveproblemfurther object of this inventionis to rovide-im'eans foraltering: the power output or a hot' gas'rengine.

still further object of this ihi'Ient'iOIiiS-tO prO vide azphase:changer device for piston type engines; A

' Other objects and advantages-of thisinvention will be:apparentas thedescriptiomproceeds';here inafter.

'lh'eidrawing- 'showsa preferred embodimentof theipresentiinventionAccordingizto the present invention; use is mad'e otfanother distinctlydifferent" device froth those mentionediand known for 'modifying thephase between the: working piston and-the displacer piston Generallyspeaking, this device is" char acterized'in that a separate crank shaftis present for the piston as wella's'for the'displac'er, which crankshafts are coupled with one another via gear wheels by means of anintermediate shaftwhich is slidable in the direction of the center-lineof this shaft. Considering each of the gear wheels. on .thesaidintermediate shaft, it is noted that"th'equotient of the gear wheeldiameter'and the angle between the direction of'pthe teeth. and' thecenter-line of the intermediate sl'i'ait is' not -equalto that of theother gear wheel, for iuse'ismade-ofgear wheels withoblique or'fieliealteeththere occurs simultaneouslywith thersli'dingtmovement of thisintermediate shaft ofiitherlatter...v Thiserotation isiflqlial-"tb theangular displacement of'th'e' some 01 appn cation on the gear wheelefthegear wheel mesiie ing therewith. Theangle' of displac'eme'nt-ofthis point ofapplication is directly propoitional to the angle whichforms the teeth it-h the-'eeiite line of the intermediate shaftinversely proportional to the gear wheel diaihet'er. If for the-twogears on the intermediate shaft these quotients are equal,onlythe-ihterinediateshatt is consequently rotated upon displacement;the shafts coupled therewithremaining at rest dur ing this rotar-ymotiomIftlie quotientsareuii equal, as in the case" according tothe invention,the angular displacement on the" one seat wheel is consequently, with adetermined displacement; not-equal to' that on the other gear" wheel;and therefor the twocrank shafts rotaterelat-i vely to one another andthe phase angle' betweenthe two cranks Varies.

A hot-gas engine is generally constructed such manner that withadeterminedphase angle between the piston'an'd the dis'pl ac'erjwhichangl-e may be, for example, 90", the maximum indicated power is"obtained. A larger phase angle im possible-from aconstruet-io'rialpoinfi of v ew cause in' thiscase the pis'ton and thedispl er would butt" e einstone 1 another as'inalier phase angle is,however, always-possible If the phase angle becomes zero; the indisatedpower is no; If the phase angle b'ecornes n-egativejg the motorrotatesin the opposite direction; The' negative value may" riseto thesame height as themaximum positiv'evalue, that is, 90"; as describedhereinafter; sothat-it-is again 'st'iinpossihleforthe piston and thedisplacer tobutt against oiiean other. The device according tetheinvention'is preferably" constructed in seen mariner-"that the phaseangle lzi'ei'iireen the? positive" and negative maximum-flvaluesis*varia'hleso" thatth'e described construction mayserve-not only forthecontrol of the power but alsofor the reversal oftliedl rection ofrotation ofthejengine: q I

Owing-t'o the fact that the displace'r? pisto'r'i can be displaced withrespect t'oth'ewoi'kingpi's ton, it is possible'to-startthe engine bymeanso'f this construction.

The invention will be eiiplained more fiillywith reference totheaccompanying' drawingi which represents, by way of exampleone embodimentthereof; Y

The drawing represents: only-"the parts of a hot-gas engine which areessential:fbr ah understa'ndingof this inventionzt A workin'g pistbn lland a displacer piston" I0beingi-aligned pistoi i means: arewconnectedzto separate 'crank 'sha itsi and [3 respectively through theintermediary of various cranks and connecting rods. Piston means II iscoupled to the crank shaft l2 by a Y or wishbone shaped connecting rodmeans I l'. A piston rod Ill attached to the piston means It] is coupledto the crankshaft I3 through the intermediary of offset pitman means l3.The phase between the piston II and the displacer I9 consequentlydepends on the phase angle between the two crank shafts l2 and I3. Sincea modification of this phase angle entails a change in the course of thepressure of the cycle, the indicated power of the engine may be variedby adjusting this phase angle.

These crank shafts are coupled with one another by means of anintermediate shaft [6 through the intermediary of screw wheels or gearmeans. Since in a hot-gas engine the speeds of the piston and of thedisplacer are equal, the ratio of transmission via this intermediateshaft and these gear wheels is 1:1. However, in order to be able tomodify the indicated power, it must be possible to modif the phase anglerelationship between the crankshafts l2 and 53. This is effected bydisplacing the intermediate shaft it, which is coupled for this purposewith a lever 29. The intermediate shaft has mounted on it two screw orgear wheels or gear means l5 and iii of which the former meshes with agear wheel 14 on the crankshaft l2 and the latter with a gear wheel I!on the crank shaft i3. The gear wheels l5 and it are constructed in suchmanner that upon displacement of the shaft l6 along its own axial lengththe shafts l2 and it perform unequal rotary motions so that the phasebetween these shafts varies. This consequently implies that upondisplacement of the shaft [6 the point of application between the gearwheels l7 and I8 is displaced through another angle than the point ofapplication between the gear wheels It and I5. With screw wheels orgears the displacement of the point of application or original contactdepends on the pitch of the teeth and on the diameter of the gear wheel,and this in such manner that the angular displacement is greateraccording as the pitch angle is larger (by pitch angle is meant theangle formed between the teeth and the center-line of the shaft), thisangular displacement being, with the same pitch angle, inverselyproportional to the gear wheel diameter. Upon displacement in thedirection of the shaft, gear wheels whose quotients of pitch angle andgear wheel diameter are equal may consequently undergo equal angledisplacements,

although the gear wheel diameters are unequal.

intermediate shaft, a maximum variation of the phase angle between thecrankshafts of the piston and of the displacer isobtained, if on the twogear wheels the angles formed between the teeth and the axis of the gearwheel are opposite. The numerical values of these quotients aretherefore preferably made equal in order that two equal gear wheelsmilled in opposite directions may suifice. On the ground of these latterconsiderations the diameters of the gear wheels I5 and I8 and thereforealso those of the gear wheels l4 and I! are all made equal to oneanother.

What we claim is:

1. In a hot-gas engine, a device for controlling its indicated power bymodifying the phase angle between its piston and displacer comprising acrank shaft of the piston, a crank shaft of the displacer, parallel gearmeans fixed to each of said shafts, an intermediate shaft, gear wheelsparallel with said gear means coupled to said intermediate shaft, saidgear wheels being coupled to said gear means respectively, said gearwheels being so proportioned that the quotient of one gear wheeldiameter and the angle between its teeth and center-line of theintermediate shaft is not equal to that of another gear wheel.

2. A device as claimed in claim 1 wherein said intermediate shaft isaxially movable with respect to said crankshafts to such an extent thatthe phase angle varies from a positive maximum value to a negativemaximum value.

3. A device as claimed in claim 1 wherein said quotients are of equalbut of opposite values.

4. A phase changing device for a hot-gas engine comprising a pistoncrankshaft, a separate displacer crankshaft parallel to the first, gearmeans fixed to said shafts respectively, an intermediate shaft parallelto said shafts, spaced gear wheels coupled to said intermediate shaft,said gear Wheels being so proportioned that the quotient of one gearwheel diameter and the angle between its teeth and the center-line ofsaid intermediate shaft is not equal to that of another gear wheelwhereby variou longitudinal movements of the same into mesh with saidrespective crankshaft gear means cause phase angle differences betweensaid crankshafts, and means for moving said intermediate shaft along itown longitudinal axis in two directions.

5. A phase changer device as claimed in claim 4 wherein saidintermediate shaft is axially movable with respect to said twocrankshafts to such an extent that said phase angle vary from positivevalues to negative values.

6. A device as described comprising aligned piston means, connecting rodmeans coupled to said means, a first one of said rod means being movablewithin one of said piston means, parallel crankshaft means coupled tosaid connecting rod means, offset pitman means, one of said crank shaftmeans being coupled to said ofiset pitman means, an intermediate shaftsubstantially interposed between said crankshaft means, gear Wheel meansfixed to said respective crankshaft means and intermediate shaft forcoupling said piston means, and means for moving said intermediate shaftwith gear wheel means thereon axially whereby the phase angle betweensaid piston means is changed.

7. A device as claimed in claim 6 wherein the structural relationship ofthe gear wheel means on said intermediate shaft is such that thequotient of the gear wheel diameter and the angle of one gear wheelmeans between its teeth and center-line of said intermediate shaft i notequal to that of another gear wheel means.

FRANCISCUS LAMBERTUS VAN WEENEN. WILLEM HENDRIK STIGTER.

REFERENCES CITED The following references are of record in th file ofthis patent:

UNITED STATES PATENTS Number Name Date 537,517 Anderson Apr. 16, 1895684,927 De Ferranti Oct. 22, 1901- 805,562 Lamplough Nov. 28, 1905921,649 Peache et al May 11, 1909 2,073,550 Crakes et al Mar. 9, 19372,245,075 Mingle June 10, 1941

